Circuits and Transmission Lines - May 2012

Electronics & Telecomm. (Semester 3)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.

Attempt any FOUR from the following

1 (a) How many trees are possible for the given graph :
(5 marks) 1 (b) By mesh analysis determine the current through 2Ω resistor :
(5 marks) 1 (c) Find the condition of reciprocity for Z parameters (5 marks) 1 (d) Find I, in the circuit if dependent voltage source is
(i) 2V₂
(ii) 1.5V₃
(5 marks) 2 (a) Find the current through 5Ω resistor. :
(10 marks) 2 (b) Find the Network function $$ \frac{V_1}{I_1}, \frac{V_2}{V_1} \ and \ \frac{V_2}{I_1} $$
(10 marks) 3 (a) The switch is changed from position 1 to position 2 at t=0, Steady state having reached before switching. Find values of
$$ i, \frac{di}{dt} \ and \ \frac{d^2i}{dt^2} \ and \ t=0^+ $$
(10 marks) 3 (b) In the network, the switch is opened at t=0. Find i(t).
(10 marks) 4 (a) Write down the tieset matrix & obtain the network equilibrium equation in matrix form using KVL. Calculate loop currents:
(10 marks) 4 (b) Determine Y & Z parameters for the network
(10 marks) 5 (a) Synthesize the following function $$ Z\left(s \right)= \frac{6\left(s+2 \right)\left(s+4 \right)}{s\left(s+3 \right)}$$
Use Foster -II Method.(8 marks) 5 (b) A driving point R-L admittance function is given by-
$$ y_{RL}\left(s \right)= \frac{s^2+6s+8}{s^2+4s+3} $$
Use cauer - I Method (6 marks) 5 (c) Synthesize the following Y_RL(s) using cauer II from
$$ Y_{RL}\left(s \right)= \frac{\left(s+1 \right)\left(s+4 \right)}{s\left(3s+4 \right)} $$
(6 marks) 6 (a) Find the current I in the network, using superposition theorem.
(10 marks) 6 (b) (i) Check the given polynomial for Hurwitz
$$ P\left(s \right)=s^5+8s^4+24s^3+28s^2+23s+6 $$(5 marks) 6 (b) (ii) Test whether $$ F\left(s \right)= \frac{{5(s+1)}^2}{s^3+2s^2+2s+40} $$ is positive real function.(5 marks) 7 (a) Find the current through 10Ω resistor (Thevenin's theorem).


(b) Determine the hybrid parameter of the network.
(20 marks)